The present invention relates to high speed data transmission lines and, more particularly, to a controlled-impedance transmission line having an inductor-assisted termination network.
High-speed data transceivers transmit data from a transmitter to a receiver over a controlled-impedance transmission line. One or typically both ends of the transmission line are resistively terminated to a reference voltage such as a power supply terminal or a ground terminal. The total effective termination resistance is preferably matched to the impedance of the transmission line to minimize reflection and distortion of the transmitted data signals. Current-mode output drivers are often used to drive resistively-terminated transmission lines since they have a relatively high output resistance. The higher the output resistance, the less effect the output driver has on the total effective termination resistance, which allows for better transmission line impedance matching.
The data transmission circuit of the present invention includes a voltage supply terminal, a resistively-terminated, controlled-impedance transmission line and an inductor coupled between the voltage supply terminal and the transmission line.
Another aspect of the present invention relates to a data transmission circuit which includes a data transmitter, a data receiver and a transmission medium having a first end coupled to the data transmitter and a second end coupled to the data receiver. A termination resistance is coupled to at least one of the first and second ends. A termination inductance is coupled to at least one of the first and second ends.
Another aspect of the present invention relates to a method of terminating a data transmission line. The method includes coupling a termination resistor between a first termination voltage terminal and the transmission line and coupling a termination inductor between a second termination voltage terminal and the transmission line.